FIBER-REINFORCED THERMOSETTING PLASTIC COMPONENT WITH A FUNCTIONAL LAYER FOR CONNECTING TO A THERMOPLASTIC COMPONENT

Abstract

A method for joining a thermoset plastic component and a thermoplastic component by bonding includes interconnecting the two components via a functional layer of the thermoset plastic component. The thermoplastic component is directly applied to the functional layer of the thermoset plastic component, such that a diffusion region is formed between the thermoplastic component and the functional layer of the thermoset plastic component.

Claims

1. A method for manufacturing an at least hardened fiber-reinforced thermosetting plastic component that can be joined to a thermoplastic component via a firm bond, the method comprising the steps of: applying one of a thermoplastic and thermoplastic/thermosetting plastic functional layer, at least in a joining area for joining to the thermoplastic component at least as early as during a hardening step on an unhardened thermosetting plastic main body which includes reinforcement fibers and a viscous thermosetting plastic matrix; and at least hardening the main body in a curing device under at least one of pressure and heat so that the functional layer is joined to the main body via a firm bond, and so that the at least hardened main body can be joined in a subsequent joining process to the thermoplastic component via the functional layer.

2. A method according to claim 1, wherein the functional layer is applied on a tool shape of the curing device, at least in a tool shape area fitting tightly on the joining area during the hardening step.

3. A method according to claim 1, wherein the functional layer is joined to the main body through adhesion so that an adhesion interface is formed between the functional layer and the main body, and wherein the functional layer includes the thermosetting/thermoplastic plastic and during the hardening step the thermosetting plastic of the thermoplastic/thermosetting plastic move towards the adhesion interface and the thermoplastic moves away from the adhesion interface.

4. A method according to claim 1, wherein the thermosetting plastic matrix is one of sprayed on the reinforcement fibers in a wet impregnation process, injected into the curing device in an injection process, and inserted as a pre-preg into the curing device together with the reinforcement fibers.

5. A method according to claim 2, wherein during the hardening step, the tool shape of the curing device is at least one of preheated to a temperature before the functional layer is sprayed on and maintained at a temperature that is at least equal to a curing temperature of at least one of the thermosetting plastic matrix and of the thermosetting plastic of the functional layer, and lower than a melting temperature of the thermoplastic of the functional layer.

6. A thermosetting plastic component for welding to a thermoplastic component, the thermosetting plastic component comprising: a cured thermosetting plastic main body; reinforcement fibers integrated into a thermosetting plastic matrix; and a functional layer at least in a joining area for joining to the thermoplastic component, the functional layer including one of a thermoplastic and thermoplastic/thermosetting plastic.

7. A thermosetting plastic component according to claim 6, wherein the functional layer is one of a sprayed layer and a foil, the functional layer being joined directly to the main body in such a way that an adhesion interface is formed between the functional layer and the main body.

8. A thermosetting plastic component according to claim 6, wherein functional layer includes the thermosetting/thermoplastic plastic and a composition of the thermosetting plastic of the functional layer is at least very similar to that one of the thermosetting plastic matrix.

9. A thermosetting plastic component according to claim 6, wherein the functional layer includes the thermosetting/thermoplastic plastic and an amount of the thermosetting plastic of the functional layer is greater in an area of the adhesion interface than in an area of a connecting surface for joining to the thermoplastic component.

10. A thermosetting plastic component according to claim 6, wherein the functional layer includes the thermosetting/thermoplastic plastic and an amount of the thermoplastic of the functional layer is at least equal to an amount of the thermosetting plastic.

11. A thermosetting plastic component according to claim 6, wherein the functional layer has a substantially homogenous thickness from 10 m to 1000 m over its entire surface.

12. A method for joining a thermoplastic component to a cured thermosetting plastic component manufactured according to the method of claim 1, the method for joining comprising: joining together the thermoplastic component and the thermosetting plastic component via a functional layer of the thermosetting plastic component so that the thermoplastic component is welded directly to the functional layer of the cured thermosetting plastic component so that a diffusion area is formed between the thermoplastic component and the functional layer of the thermosetting plastic component.

13. A method according to claim 12, wherein at least one of the thermoplastic component and the functional layer are at least one of preheated, melted on, or pressed against one another before welding at least in their respective joining areas.

14. A composite part comprising: a cured thermosetting plastic component manufactured according to the method of claim 1; and a thermoplastic component welded directly to a functional layer of the cured thermosetting plastic component so that a diffusion area is formed between the thermoplastic component and the functional layer.

15. A composite part according to claim 14, wherein the functional layer includes the thermosetting/thermoplastic plastic, and a composition of the thermoplastic of the thermoplastic component is at least very similar to that of the functional layer.

16. A method according to claim 1, wherein the functional layer is transferred to the unhardened main body when the tool shape is closed.

17. A method according to claim 5, wherein the curing temperature is between 100 C. and 200 C. and the melting temperature is between 100 C. and 300 C.

18. A method according to claim 17, wherein the curing temperature is about 120 C. and the melting temperature is about 200 C.

19. A thermosetting plastic component according to claim 11, wherein the thickness is from about 150 m to about 750 m

20. A method according to claim 12, wherein at least one of the cured thermosetting plastic component is inserted as insert in an injection mold in an injection molding process and the thermoplastic component is sprayed as thermoplastic molten mass directly on the functional layer of the thermosetting plastic component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Additional advantages of the invention are described in the following embodiments, which show:

[0047] FIG. 1 is a cross-sectional view of an area of a fiber-reinforced thermosetting plastic component with a functional layer.

[0048] FIG. 2 is a cross-sectional view of an area of a fiber-reinforced thermosetting plastic component and a thermoplastic component before joining, especially welding.

[0049] FIG. 3 is a cross-sectional view of a joining area of a composite part with a thermoplastic component in cross section connected, especially welded on, to a functional layer of the thermosetting plastic component.

DETAILED DESCRIPTION

[0050] FIG. 1 shows a cross section through a thermosetting plastic component 1 that comprises a main body 2 and a functional layer 3. Here, the thermosetting plastic component 1 is formed as a fiber-reinforced thermosetting plastic component. Thus, the main body 2 comprises reinforcement fibers 4 embedded in a plastic matrix 5. The reinforcement fibers can be made of glass, carbon and/or aramid fibers. In this embodiment, the reinforcement fibers 4 are formed as carbon fibers. The carbon fibers can be formed as short-cut fibers, short-cut threads, bands, or as is the case here, as fabric mats in the main body 2. Furthermore, it is also conceivable for the reinforcement fibers to be incorporated as clutches, i.e. at least two fabric mats placed above one another. The matrix 5 is here a thermosetting plastic, especially an epoxy resin or polyurethane resin. The thermosetting plastic matrix 5 is cured here and gives the reinforcement fibers 4 dimensional stability. The reinforcement fibers 4 serve primarily to give the main body 2 or thermosetting plastic component 1 the needed strength.

[0051] The thermosetting plastic main body 2 can have any form. Thus, the main body 2 can be, for example, a vehicle body part or also its inner covering. Usually, such thermosetting plastic main bodies or thermosetting plastic components have complex structural geometry, particularly with free-forming surfaces and/or undercuts.

[0052] A basic problem that such thermosetting plastic components have is that after curing they can only be joined to additional components using very time-consuming and expensive methods. Additionally, these methods have the disadvantage that the bonding quality is not particularly good so the danger exists that these two components will detach from one another if subject to a load.

[0053] According to the disclosure and FIG. 1, the thermosetting plastic component 1 therefore has the functional layer 3, which is a thermoplastic or a mixture from a thermoplastic and thermosetting plastic. In a thermoplastic/thermosetting plastic functional layer 3, the proportion of thermosetting plastic to thermoplastic is preferably 1:4, 1:3, 1:2 or very preferably 1:1.

[0054] The functional layer 3 is directly joined to the main body 2 via adhesion, especially stuck together. Thus, an adhesion interface 6 has been formed between the functional layer 3 and the main body 2. In this case, the functional layer 3 canas shown in FIG. 1be joined exclusively to the thermosetting plastic matrix 5 of the main body or also additionally or alternatively to the reinforcement fibers 4. The adhesion interface 6 represents a clear transition from the thermosetting plastic matrix 5 to the thermoplastic or thermoplastic/thermosetting plastic functional layer 3. No diffusion area has been formed between them. Also, no joining agent, especially glue and/or primer, has been arranged.

[0055] The functional layer 3 is arranged in a joining area 7a of the thermosetting plastic component 1. On its side that faces away from the main body 2, the functional layer 3 has a connecting area 8 on which the thermoplastic component 9 intended for this purpose can be connected, especially welded (cf. FIGS. 2 & 3). The thermosetting plastic component 1 can also have several joining areas 7a formed in this way in which it is possible to be connected, especially welded, to one or several thermoplastic components 9.

[0056] Compared to the main body 2, the functional layer 3 has been formed very thinly. Preferably, it has a thickness from 10 m to 1000 m, especially from 150 m to 750 m. Especially preferable, however, is a very thin functional layer 3 having a thickness from 10 m to 250 m, especially up to 200 m, very preferably up to 150 m.

[0057] Such thin functional layers can be made through a spraying process. To achieve this, the reinforcement fibers 4, especially carbon fibers, are inserted into the viscous thermosetting plastic matrix 5 to form the main body in a curing device not shown here. Such a curing device can be an oven, autoclave or vacuum press, for example. In this curing device, the thermosetting plastic matrix 5 is hardened and/or cured under pressure and/or heat. However, before this hardening process, it is provided with the functional layer 3 in the joining area 7a, in which the thermosetting plastic component 1 will be joined, especially welded, to the thermoplastic component 9 intended for this purpose.

[0058] To make such a functional layer 3 very thin compared to foils, it is sprayed on the viscous thermosetting plastic matrix 5 and/or the reinforcement fibers 4 before or during the hardening process. Alternatively or additionally, the thermoplastic or thermoplastic/thermosetting plastic mixture forming the functional layer 3 can be sprayed on a tool shape of the curing device not shown here. In this case, it is especially advantageous if the thermoplastic and/or thermosetting plastic, with which the functional layer 3 is formed, sits tightly on the joining area 7a of the main body 2 in the area of the tool shape that is being sprayed during the hardening process. After spraying the functional layer 3 on the tool shape by placing the reinforcement fibers 4 together with the viscous thermosetting plastic matrix 5, especially as pre-preg, contact between the functional layer 3 and the main body 2 can take place in the tool shape. Alternately, however, contact can also take place until the tool is closed and/or the viscous thermosetting plastic matrix 5 is injected into the closed tool. The very strong adhesion interface 6 via which the functional layer 3 is joined to the main body 2 is formed during the ensuing hardening process, wherein no additional glues and/or primers are used.

[0059] An important advantage of the method according to the disclosure in which the functional layer is sprayed is that the entire surface of the functional layer 3 sits tightly on the main body 2. This is particularly noticeable in a complex structural geometry because in this case a functional layer 3 formed as foil would form so-called dry spots that eventually would weaken the bond between functional layer 3 and main body 2.

[0060] A very good adhesion of the functional layer 3 to the main body 2 and at the same time a very strong connection, especially welding connection, to the thermoplastic component 9 shown in FIG. 3 can be ensured if the functional layer 3 has both thermoplastic and thermosetting plastic amounts. Such a thermoplastic/thermosetting plastic functional layer 3 is characterized especially by the fact that the thermosetting plastic amounts of the functional layer 3 are higher in the area of the adhesion interface 6 than in the connecting surface 8 intended for connection to the thermoplastic component 9. Furthermore, a very strong adhesion between functional layer 3 and main body 2 is favored if the thermosetting plastic of the thermoplastic/thermosetting plastic functional layer 3 is identical or is at least very similar to the thermosetting plastic matrix 5. Suitable thermosetting plastics for this are preferably epoxy resins or polyurethane resins.

[0061] FIG. 2 shows a partial area of the fiber-reinforced thermosetting plastic component 1 in cross section before it is joined, especially welded, to the thermoplastic component 9. To achieve this, the fiber-reinforced thermosetting plastic component 1 can be placed as insert into an injection molding device not shown here and be joined, especially welded, to it by direct spraying of the thermoplastic component 9 available as thermoplastic molten mass in the area of the joining area 7a of the thermosetting plastic component 1. Thus, the thermoplastic molten mass is joined, especially welded, to the functional layer 3 of the thermosetting plastic component 1, at the same time formingin conjunction with the injection moldthe final shape of the thermoplastic component 9 as functional element.

[0062] Alternatively, however, some areas of the finished thermoplastic component 9 can, especially as functional element, also be pre-heated and/or melted on in its joining area 7b, and while this occurs or after this preheating and/or melting process has been completed, be pressed with its melted-on joining area 7b on the functional layer 3 of the thermosetting plastic component 1, in its joining area 7a. In this case, the thermoplastic component 9 is melted with the functional layer 3. Additionally or alternatively, however, the functional layer 3 can also be preheated and/or melted on. This joining process can take place in a bonding device made for this purpose.

[0063] A composite part 10 shown in FIG. 3 is manufactured via the two methods mentioned above. It is characterized by the fact that the thermoplastic component 9 is joined, especially welded, to the fiber-reinforced thermosetting plastic part 1, wherein the connection between these two parts is made possible by the functional layer 3. When the thermoplastic component 9 is being joined, especially welded, to the thermosetting plastic component 1, a diffusion area 11 is formed between the functional layer 3 of the thermosetting plastic part 1 and the thermoplastic part 9. This diffusion area 11 is very strongly formed when the thermoplastic of the thermoplastic component 9 is identical to the thermoplastic or thermoplastic/thermosetting plastic functional layer 3 or at least very similar to it. Suitable for this is any industrially usable thermoplastic, but particularly suitable is ABS and/or a polyamide, especially polyamide 11 and/or 12.

[0064] As can be recognized in the cross-sectional view shown in FIG. 3, the functional layer 3 cannot be fully melted on. The fiber-reinforced thermosetting plastic main body 2 of the thermosetting plastic component 1 and the thermoplastic component 9 joined with it are therefore separated by a remaining part of the thermoplastic or thermoplastic/thermosetting plastic functional layer 3. According to FIG. 3, the joining areas 7a, 7b of the two parts are melted together and as a result of this form the diffusion area 11, which ensures a very firm bond between the thermoplastic part 9 and the thermosetting plastic component.

[0065] FIGS. 1 & 3 show in each case only a section of a thermosetting plastic component and/or a thermoplastic component 9 or one composite part 10 comprising one of these two components. The thermosetting plastic component 1 can have several joining areas 7a formed in this way in which it can be joined or is already joined to one or several thermoplastic components 9, which are preferably functional elements, especially reinforcing braces and/or fastening areas, preferably clips, eyelets or the like. It is also conceivable for the entire surface of the thermosetting plastic component to be coated with the corresponding functional layer 3. To achieve this, it is recommended to spray the entire surface of the thermosetting plastic component 1, especially its main body 2, with a thermoplastic available in liquid, paste, powder and/or granulate form so the functional layer 3 can be formed before it is cured.

[0066] The present invention is not restricted to the embodiments shown and described here. Deviations within the framework of the patent claims are just as possible as a combination of the characteristics, even if they are shown and described in different embodiments.

LIST OF REFERENCE CHARACTERS

[0067] 1 Thermosetting plastic component [0068] 2 Main body [0069] 3 Functional layer [0070] 4 Reinforcement fibers [0071] 5 Thermosetting plastic matrix [0072] 6 Adhesion interface [0073] 7 Joining area [0074] 8 Connecting surface [0075] 9 Thermoplastic component [0076] 10 Composite part [0077] 11 Diffusion area